This application is related to and claims priority from Japanese Patent Applications No. Hei. 11-234200 filed on Aug. 20, 1999, No. 2000-141197 filed on May 15, 2000, and No. 2000-164032 filed on Jun. 1, 2000, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a vehicle air-conditioning system provided with an air-conditioning unit for controlling temperature of a passenger compartment. More particularly, the present invention relates to a vehicle air-conditioning system collectively arranging, at least equal to or more than one piece of electrical members such as a blower controller and sensors used for an air-conditioning on an electrical circuit board on which a microcomputer including functions at least CPU, a memory and the like is mounted. Further, the electrical circuit board is integrally mounted with the air-conditioning unit.
2. Description of Related Art
In a conventional vehicle air-conditioning system described in JP-U-62-117480, even when a temperature sensitive portion of a thermal-switch is failed, maintenance of the failed portion can be easily performed without removing an evaporator by providing a cover body on a side surface of an evaporator case for containing the evaporator of a refrigerating cycle, and by installing the thermal-switch having the temperature sensitive portion for sensing temperature of the evaporator in the cover body.
Further, in a general air-conditioning system for a vehicle, as illustrated in FIG. 18, the system is provided with an air-conditioning unit 100 for air-conditioning inside a passenger compartment and an air-conditioning ECU 110 for controlling respective component of the air-conditioning unit 100. In the meantime, the air-conditioning unit 100 has an evaporator case 101 for forming an air passage through which air flows. A blower, an evaporator, a heater core, an air mix door, and a mode switching door are disposed inside the evaporator case 101. Further, a cover body 103 having a connecting port 102 coupled to the blower is attached to a side surface of the evaporator.
Further, the air-conditioning ECU 110 is a device in which the well known microcomputer constructed by including functions, for example, CPU, memories (ROM and RAM), an input/output circuit and the like, is mounted on one board (an electrical circuit board) called a PC board (a printed circuit board). Based on sensor signals from control sensors such as a post-evaporator temperature sensor 104 and switch signals from various switches installed in an air-conditioning operation panel 105, a blower controller 106 for driving the blower, a servomotor 107 for driving the air mix door, and a servomotor 108 for driving the mode switching door are controlled.
Electrical members such as the post-evaporator temperature sensor 104, the air-conditioning operating panel 105, the blower controller 106 and the servomotors 107 and 108, are installed respectively independently in an interior portion or in the vicinity of an instrument panel. With this arrangement, respective electrical members for controlling the air-conditioning unit are electrically connected with one another by means of a plurality of pieces of wire harness 109.
However, in the vehicle air-conditioning system disclosed in JP-U-62-117480, since only one piece of the thermo-switch is provided on the cover body, no effect can be is found such as a decrease in the number of electrical wires of the wire harness 109 and space saving.
Further, in the conventional vehicle air-conditioning system as illustrated in FIG. 17, since the electrical members for controlling air-conditioning operation are conducted by means of a plurality of pieces of the wire harness 109 so that the air-conditioning ECU 110 is electrically connected to various sensors or to various switches, the number of electrical wires of the wire harness is increased. Therefore, a mounting space of the system on a vehicle becomes larger, assembling steps becomes larger, and the system is manufactured in a high cost.
In addition, heat-generating members such as the blower controller 106 are mounted to protrude in an interior portion of the evaporator case 101 by opening holes therein so that the heat-generating members is made in contact with cold air cooled by the evaporator. However, according to their mounting positions, there cause an increase in noise due to a draft resistance or the like. On the other hand, when the heat-generating members are mounted on the evaporator case 101 so as not too much to be protruded inside the air passage, the heat-generating members are not effectively cooled, and operation performance of the heat-generating members may be decreased.
It is an object of the invention is to provide an air-conditioning system for a vehicle, in which the number of electrical wires of a wire harness connecting control circuit members to an electrical member, for performing signal input/output operation between the control circuit members, can be reduced and an attachment space can be reduced.
It is an another object of the invention is to provide an air-conditioning system for a vehicle possible to be decreased in manufacturing cost by reducing assembling steps of air-conditioning control circuit members and electrical members.
It is a further object of the invention to provide an air-conditioning system for a vehicle capable of securing contact pressure of a temperature sensitive portion of a temperature sensor to a side surface of an evaporator.
It is a still further object of the invention to provide an air-conditioning system for a vehicle, in which components are readily attached with improved maintenance performance.
According to a first aspect of the present invention, in a vehicle air-conditioning system, a plurality of control circuit members having at least functions of CPU and memory are mounted on the electrical circuit board disposed integrally with an air duct of an air-conditioning unit, and an electrical member which electrically operates when electrical power is applied thereto is mounted to the electrical circuit board to perform signal input/output operation between the control circuit members. Therefore, wire number of wire harness connecting the control circuit members and an at least one of electrical parts of the electrical member can be reduced, and attachment space of the vehicle air-conditioning system can be reduced. Accordingly, assembling steps of at least one of the electrical parts of the electrical member and the control circuit members can be reduced, and production cost of the vehicle air-conditioning system can be reduced.
Preferably, the electrical circuit board is attached to a side surface of a cooling heat exchanger. For example, the electrical circuit board is attached at a detachable side of an interior fluid pipe of the cooling heat exchanger. Therefore, a detaching operation of the cooling heat exchanger and a change of the electrical member can be readily performed in one side direction.
According to a second aspect of the present invention, a vehicle air-conditioning system includes a cooling heat exchanger for cooling heat exchanger for cooling air blown into a passenger compartment, a cooler case for accommodating the cooling heat exchanger therein, a case cover disposed in the cooler case at a side of the evaporator to cover an operation window opening of the cooler case, a temperature sensor having a temperature-sensitive portion disposed to contact a side surface of the cooling heat exchanger, and an electrical circuit board. On an electrical circuit board, a plurality of control circuit members having at least functions of CPU and memory, and an electrical member which electrically operates when electrical power is applied thereto and performs signal input/output operation between the control circuit members collectively are mounted. The electrical circuit board is disposed integrally with an exterior wall surface of the case cover, and the temperature sensor is mechanically attached to the electrical circuit board to be electrically connected with at least any one of the control circuit members and the electrical member. Thus, in the collective arrangement of the control circuit members and the electrical member, a peripheral temperature of the case cover is not affected to the temperature sensitive portion of the temperature sensor, and the temperature sensor can accurately detect the side temperature of the cooling heat exchanger.
Preferably, the case cover includes a sensor-pressing portion for pressing the temperature sensitive portion toward the side surface of the cooling heat exchanger, and the sensor-pressing portion is disposed between an interior wall surface of the case cover and the temperature sensitive portion to be elastically deformed. Therefore, a contact pressure of the temperature sensitive portion of the temperature sensor to the side surface of the cooling heat exchanger can be maintained.
According to a third aspect of the present invention, a housing is formed separately relative to an air duct made of a first resin material, and the housing is made of a second resin material having a thermal contraction smaller than that of the first resin material. Therefore, the housing is hardly deformed during molding. Thus, when plural control circuit members and at least one electrical member are collectively disposed within the housing, an axial engagement of an actuator such as a servomotor can be made simple, for example. Thus, the air-conditioning system is readily assembled and improves maintenance performance.